harfbuzz/src/hb-fallback-shape.cc

150 lines
3.9 KiB
C++

/*
* Copyright © 2011 Google, Inc.
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Google Author(s): Behdad Esfahbod
*/
#define HB_SHAPER fallback
#include "hb-shaper-impl.hh"
HB_SHAPER_DATA_ENSURE_DEFINE(fallback, face)
HB_SHAPER_DATA_ENSURE_DEFINE(fallback, font)
/*
* shaper face data
*/
struct hb_fallback_face_data_t {};
hb_fallback_face_data_t *
_hb_fallback_shaper_face_data_create (hb_face_t *face HB_UNUSED)
{
return (hb_fallback_face_data_t *) HB_SHAPER_DATA_SUCCEEDED;
}
void
_hb_fallback_shaper_face_data_destroy (hb_fallback_face_data_t *data HB_UNUSED)
{
}
/*
* shaper font data
*/
struct hb_fallback_font_data_t {};
hb_fallback_font_data_t *
_hb_fallback_shaper_font_data_create (hb_font_t *font HB_UNUSED)
{
return (hb_fallback_font_data_t *) HB_SHAPER_DATA_SUCCEEDED;
}
void
_hb_fallback_shaper_font_data_destroy (hb_fallback_font_data_t *data HB_UNUSED)
{
}
/*
* shaper shape_plan data
*/
struct hb_fallback_shape_plan_data_t {};
hb_fallback_shape_plan_data_t *
_hb_fallback_shaper_shape_plan_data_create (hb_shape_plan_t *shape_plan HB_UNUSED,
const hb_feature_t *user_features HB_UNUSED,
unsigned int num_user_features HB_UNUSED,
const int *coords HB_UNUSED,
unsigned int num_coords HB_UNUSED)
{
return (hb_fallback_shape_plan_data_t *) HB_SHAPER_DATA_SUCCEEDED;
}
void
_hb_fallback_shaper_shape_plan_data_destroy (hb_fallback_shape_plan_data_t *data HB_UNUSED)
{
}
/*
* shaper
*/
hb_bool_t
_hb_fallback_shape (hb_shape_plan_t *shape_plan HB_UNUSED,
hb_font_t *font,
hb_buffer_t *buffer,
const hb_feature_t *features HB_UNUSED,
unsigned int num_features HB_UNUSED)
{
/* TODO
*
* - Apply fallback kern.
* - Handle Variation Selectors?
* - Apply normalization?
*
* This will make the fallback shaper into a dumb "TrueType"
* shaper which many people unfortunately still request.
*/
hb_codepoint_t space;
bool has_space = (bool) font->get_nominal_glyph (' ', &space);
buffer->clear_positions ();
hb_direction_t direction = buffer->props.direction;
hb_unicode_funcs_t *unicode = buffer->unicode;
unsigned int count = buffer->len;
hb_glyph_info_t *info = buffer->info;
hb_glyph_position_t *pos = buffer->pos;
for (unsigned int i = 0; i < count; i++)
{
if (has_space && unicode->is_default_ignorable (info[i].codepoint)) {
info[i].codepoint = space;
pos[i].x_advance = 0;
pos[i].y_advance = 0;
continue;
}
(void) font->get_nominal_glyph (info[i].codepoint, &info[i].codepoint);
font->get_glyph_advance_for_direction (info[i].codepoint,
direction,
&pos[i].x_advance,
&pos[i].y_advance);
font->subtract_glyph_origin_for_direction (info[i].codepoint,
direction,
&pos[i].x_offset,
&pos[i].y_offset);
}
if (HB_DIRECTION_IS_BACKWARD (direction))
hb_buffer_reverse (buffer);
buffer->safe_to_break_all ();
return true;
}